Which bike for city commuting, triathlon AND touring?

I've only got the money to buy 1 bike.

I suppose a hybrid bike is best for city cycling, which I do every day, and involes lots of stopping at traffic lights, roundabouts and juctions. I don't think racer handle bars are good for city cycling and the tyres aren't good for the changeable road surfaces in the city either. I also definately need to have back paniers for carrying things.

However, I'd like to have a bike for the occasional triathlon, (a couple of times a year), but also one which can be used for longer distance touring sometimes (once or twice a year).

So shall I get:
(1) A fast light hybrid and then especially for triathlons or touring change (i) handle bars to racer ones (ii) lower handle bars and raise seat (iii) put clipless pedals on and (iv) put tribars on also?

(2) A road bike and put clipless pedals and tribars on for triathlons? (But perhaps this can't take back paniers?)

(3) A touring bike and put clipless pedals and tri bars on for triathlons?

It is easy to change handle bars on a hybrid to

1. I was in the same situation some time ago, and went for a city hybrid.
   I changed the tyres to fast road tyres, and changed the bars from slightly raised to flat, with aero bars bolted on. I find this gives a good variety of positions for the hands, and isn’t as bad on my back as dropped bars were.
   The bike I got was a Giant CRS, there are different models in the range, from the base model up to the semi-composite framed version, so there should be one to fit your budget.
   It has the brackets for panniers and mud guards, and you can easily remove the accessories for when you want to race.
   I must admit that last year I had the opportunity to purchase a second bike, which I now use for day to day use, and save the CRS for weekends and races.
   Good luck, and I hope this helps.

2. The best way to find out is to ride a few of each type. I ride a Bianchi Via nirone around cities, and in London and roundabouts and traffic lights really aren’t a problem.

   I’ve also found that road bikes (not all) have attachments for paniers as well!

   I would also say don’t do a triathlon on a touring bike… the frame geometries are not right for that kind of high intensity time trialing race. If your priority is commuting and less racing, get the touring bike. If you’re serious about triathlon racing and building your fitness to a high level, then get a road bike! You will struggle getting a decent time at Tris with a touring bike, I assure you…

   Have fun! Consider Trek 7500 or 7500FX, Trek 520, Felt F70, Specialized Allez or Bianchi C2C range.

3. Of the three, a touring bike is the most versatile. Road bars are fine in city traffic if they are at the right height, and the drops work well when you need to ride into a head wind. Tires can be big enough to handle rough roads, and an aerobar can be added for triathlons. I own 5 bikes for different types of riding, but if I had to choose one it would be my touring bike, I use it for training rides in the spring with the race team I belong to, it is a great commuter, and capable of a cross country trip if I could find the time.